IITAA

O Instituto de Investigação e Tecnologia da Agronomia e Meio Ambiente (IITAA) desenvolve trabalho de investigação com o objetivo de perseguir estudos em diversas áreas, como a caracterização / previsão do clima insular e os efeitos das mudanças globais em comunidades do oceano para os to... Ler mais »

PUBLICAÇÕES

Effect of rising atmospheric carbon dioxide on the marine nitrogen fixer Trichodesmium

Clima, Ambiente e Paisagem

Referência

Barcelos e Ramos, J., H. Biswas, K. G. Schulz, J. LaRoche, and U. Riebesell (2007), Effect of rising atmospheric carbon
dioxide on the marine nitrogen fixer Trichodesmium, Global Biogeochem. Cycles, 21, GB2028, doi:10.1029/2006GB002898.

Resumo

Diazotrophic (N2-fixing) cyanobacteria provide the biological source of new nitrogen for large parts of the ocean. However, little is known about their sensitivity to global change. Here we show that the single most important nitrogen fixer in today’s ocean,Trichodesmium, is strongly affected by changes in CO2 concentrations. Cell division rate doubled with rising CO2 (glacial to projected year 2100 levels) prompting lower carbon, nitrogen and phosphorus cellular contents, and reduced cell dimensions.N2 fixation rates per unit of phosphorus utilization as well as C:P and N:P ratios more than doubled at high CO2, with no change in C:N ratios. This could enhance the productivity of N-limited oligotrophic oceans, drive some of these areas into P limitation, and increase biological carbon sequestration in the ocean. The observed CO2 sensitivity of Trichodesmium could thereby provide a strong negative feedback to atmospheric COincrease.

Sbado, 23 Junho, 2007

Equipa

Joana Barcelos e Ramos
Membro Integrado (Investigador Post-Doc)

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